Pharmaceutical composition with improved bioavailability of inositol phosphate

ABSTRACT

The invention relates to an inositol phosphate containing pharmaceutical composition which comprises a nitrogen-containing compound for improvement of the bioavailability of the inositol phosphate in mammals including man at non-parenteral administration. The invention also covers the use of at least one nitrogen-containing compound for the preparing of an inositol phosphate containing medicament with improved bioavailibility of inositol phosphate in mammals including man at non-parenteral administration.

This application is a 371 of PCT/SE93/00144, filed Feb. 23, 1993.

The present invention relates to an inositol phosphate containing pharmaceutical composition with improved bioavailability of inositol phosphate and the use of at least one nitrogen-containing compound for the preparation of an inositol phosphate containing medicament with improved bioavailability of inositol phosphate.

Hydrophilic and ionized drugs must often encounter rather poor penetration of the epithelial barriers to the capillaries of the portal circulation as most of these types of substances are transported by passive diffusion. Inositol phosphates belong to this group.

Normally it is the unionized fraction of the drug that partitions across the lipid membranes and this fraction is most often small over the pH-range encountered in the gastrointestinal tract.

It is known from the literature, for example Jonkman J. H. G. and Hunt C. A. (1983) Pharmaceutische Weekblad Scientific Edition 5, 41-48, that a combination of a quarternary ammonium compound and sulfonic acids are absorbed to a small extent after oral administration. The absorption is described as poor and in many cases contradictory.

In the literature nothing has been described about the use of counter ions such as nitrogen-containing compounds together with inositol phosphates for improvement of the bioavailability.

At oral administration the properties of inositol phosphates per se result in limitations in respect of the uptake of the compounds from the intestine. In order to optimize the effect of these substances in the body it is desirable that as large a portion as possible of the added amount can be utilized effectively. Thereby the added amount can be reduced which is advantageous for the patient for example when the drug D-myo-inositol-1,2,6-trisphosphate (IP₃) is used.

According to the present invention it has now quite surprisingly been possible to meet the above desire and bring about an inositol phosphate containing pharmaceutical composition which comprises a nitrogen-containing compound for improvement of the bioavailability of the inositol phosphate in mammals including man at non-parenteral administration.

The expression bioavailability stands for a measurement of how large a portion of an administrated drug that occurs in the blood stream when the way of administration of the drug is non-parenteral. The term thus shows the amount of the drug that has been able to penetrate membrane barriers after for example oral administration, topical administration or intraperitoneal administration.

The nitrogen-containing compound can be for example a quarternary ammonium ion, a tertiary amine, a diamine, a polyamine, an amino acid or a derivative thereof.

The quarternary ammonium ions used according to the invention is defined as follows:

1. ⁺ N(R₁ R₂ R₃ R₄) wherein R₁, R₂, R₃ and R₄ independently are

(i) hydrogen

(ii) a straight or branched alkyl with 1 to 24 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl and docosyl;

(iii) cycloalkyl with 3 to 16 carbon atoms such as cyclopropyl, cyclopentyl and cyclohexyl;

(iv) alkenyl with 2 to 24 carbon atoms such as vinyl, allyl, propenyl, octadienyl, octenyl, decenyl, dodecenyl, tetradecenyl, hexadecenyl, octadecenyl, octadecadienyl, nonadecenyl, octadecatrienyl and arachidonyl;

(v) cycloalkenyl with 5 to 16 carbon atoms such as cyclopentenyl, cyclopentadienyl, cyclohexenyl and cyclohexadienyl;

(vi) aryl with 6 to 24 carbon atoms such as phenyl and biphenyl;

(vii) aralkyl, alkaryl, aralkenyl, alkenylaryl wherein alkyl, aryl and alkenyl are as previously defined.

The above groups (ii) to (vii) are unsubstituted or substituted with hydroxy; oxo; alkoxy; aryloxy; carboxy; esterified carboxy; amino; substituted amino; formyl; acyl; acyloxy; or acylamine.

Preferred nitrogen-containing compounds in this group according to the invention are N-tetramethylammonium, N-tetraethylammonium, N-tetrapropylammonium, N-tetrabutylammonium, N-tetrapentylammonium, N-tetrahexylammonium, N-tetraheptylammonium and N-tetraoctylammonium. Other preferred nitrogen-containing compound are N-decyltrimethylammonium, N-undecyltrimethylammonium, N-dodecyltrimethylammonium, N-tridecyltrimethylammonium, N-tetradecyltrimethylammonoum, N-pentadecyltrimethylammonium, N-hexadecyltrimethylammonium, N-benzyltrimethylammonium.

2. ⁺ N(R₁ R₂ R₃)R₅ wherein R₁, R₂, R₃ are as defined above and preferably methyl, ethyl or propyl and wherein R₅ is

(i) --(CH₂)_(n) OCOR₆ wherein n≧2 and wherein R₆ is a straight or branched alkyl or alkenyl with 1 to 24 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl eicosyl, docosyl, vinyl, allyl, octadienyl, octenyl, decenyl, dodecenyl, tetradecenyl, hexadecenyl, octadecenyl, octadecadienyl nonadecenyl, octadecatrienyl and/or arachidonyl or where R₆ is --CH₂ CH(CH₃)OCOR₁, --CH(CH₃)CH₂ OCOR₁, --CH₂ CH(OCOR₁)CH₂ OCOR₁, --CH(CH₂ OCOR₁)₂, --CH₂ CH(OH)CH₂ OCOR₁, --CH₂ CH(CH₂ OH)OCOR₁, --CH(CH₂ OH)CH₂ OCOR₁ or --CH(CH₃)COOR₁ wherein R₁ is as defined above.

(ii) --(CH₂)_(n) OR₆ wherein n and R₆ are as defined above.

Preferred nitrogen-containing coumpounds in this group according to the invention are N-decanoyloxypropyltrimethylammonium, N-undecanoyloxypropyltrimethylammonium, N-dodecanoyloxypropyltrimethylammonium, N-tridecanoyloxypropyltrimethylammonium, N-tetradecanoyloxypropyltrimethylammonium, N-pentadecanoyloxypropyltrimethylammonium, N-hexadecanoyloxypropyltrimethylammonium, N-decanoyloxyethyltrimethylammonium, N-undecanoyloxyethyltrimethylammonium, N-dodecanoyloxy ethyltrimethylammonium, N-tridecanoyloxyethyltrimethylammonium, N-tetradecanoyloxyethyltrimethylammonium, N-pentadecanoyloxyethyltrimethyl-ammonium, N-hexadecanoyloxyethyltrimethylammonium, N-decyloxypropyltrimethylammonium, N-undecyloxypropyltrimethylammonium, N-dodecyloxypropyltrimethylammonium, N-tridecyloxypropyltrimethylammonium, N-tetradecyloxypropyltrimethylammonium, N-pentadecyloxypropyltrimethylammonium, N-hexadecyloxypropyltrimethylammonium, N-decyloxyethyltrimethylammonium, N-undecyloxyethyltrimethylammonium, N-dodecyloxyethyltrimethylammonium, N-tridecyloxyethyltrimethylammonium, N-tetradecyloxyethyltrimethylammonium, N-pentadecyloxyethyltrimethylammonium, N-hexadecyloxytrimethylammonium.

(iii) --(C(R₇)₂)_(n) COOR₆ wherein n≧1 and wherein R₇ is hydrogen and/or lower straight or branched alkyl such as methyl, ethyl, propyl, and/or butyl and wherein R₆ is as defined above. Preferably n=1 and R₆ is hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl or hexadecyl.

(iv) --C(R₇)₂ OCOR₆ wherein R₇ is hydrogen and/or lower straight or branched alkyl such as methyl, ethyl, propyl and/or butyl and wherein R₆ is as defined above. Preferably R₆ is hexyl, hepty, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl or hexadecyl.

(v) --C(R₇)₂)_(n) (C(R₈)₂)_(m) COOR₆ wherein n≧1, m≧1 and wherein R₇ is as defined above, wherein R₈ is hydrogen, hydroxyl, alkyloxy or acyloxy and wherein R₆ is as defined above. Preferably the compounds are selected from the following group:

^(+N)(CH₃)₃ CH₂ CHOHCH₂ COOR₆ wherein R₆ is hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tridecyl, tetradecyl, pentadecyl or hexadecyl;

⁺ N(CH₃)₃ CH₂ CHOR₉ CH₂ COOR₆ wherein R₆ is as defined above and wherein R₉ is lower alkyl such as methyl, ethyl and propyl or lower acyl such as formyl, acetyl or propionyl.

(vi) --C(R₇)₂)_(n) CONR₇ CR₇ COOR₁ wherein n≧1 and wherein R₇ is hydrogen and/or lower straight or branched alkyl such as methyl, ethyl, propyl and/or butyl and wherein R₁ is as defined above. Preferred n=1 and R₇ is hydrogen.

In one embodiment of this type of the invention R₁, R₂ and/or R₃ are

i) hydrogen;

ii) a straight or branched alkyl selected from the group of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and/or octyl;

and R₅ is

--(CH₂)OCOR₆ wherein R₆ is selected from the group of hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl and/or hexadecyl.

In another embodiment of the invention R₁, R₂ and/or R₃ are

i) hydrogen;

ii) a straight or branched alkyl selected from the group of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and/or octyl;

and R₅ is

(CH₂)OR₆ wherein R₆ is selected from the group of hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl and/or hexadecyl.

In another embodiment of the invention R₁, R₂ and/or R₃ are

i) hydrogen;

ii) a straight or branched alkyl selected from the group of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and/or octyl;

and R₅ is

--C(R₇)₂ COOR₆ wherein R₆ is selected from the group of hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl and/or hexadecyl or from the group of --CH₂ CH(CH₃)OCOR₁, --CH(CH₃)CH₂ OCOR₁, --CH₂ CH(OCOR₁)CH₂ OCOR₁, --CH(CH₂ OCOR₁)₂, --CH₂ CH(OH)CH₂ OCOR₁, --CH₂ CH(CH₂ OH)OCOR₁, --CH(CH₂ OH)CH₂ OCOR₁ or --CH(CH₃)COOR₁ and wherein R₇ is

i) hydrogen;

ii) a straight or branched alkyl selected from the group of methyl, ethyl, propyl and/or butyl;

In still another preferred embodiment of the invention R₁, R₂ and/or R₃ are

i) hydrogen;

ii) a straight or branched alkyl selected from the group of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and/or octyl;

and R₅ is

--C(R₇)₂ OCOR₆ wherein R₆ is selected from the group of hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl and/or hexadecyl and wherein R₇ is

i) hydrogen;

ii) a straight or branched alkyl selected from the group of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and/or octyl;

3. A heterocyclic group containing at least one nitrogen atom such as C₅ H₄ R₁₀ NR₁₁ wherein R₁₀ is hydrogen, lower alkyl, carboxy, esterified carboxy or carboxamide and wherein R₁₁ is

(i) R₁ as defined above

(ii) --(C(R₇)₂)_(n) OCOR₆ wherein n≧1 and wherein R₇ is hydrogen or lower alkyl such as methyl, ethyl, propyl and/or butyl and R₆ is as defined above.

Preferred nitrogen-containing compounds are 1-methyl-2-pyridine amide, 1-ethyl-2-pyridine amide, 1-propyl-2-pyridine amide, 1-methyl-3-pyridine amide, 1-ethyl-3-pyridine amide, 1-propyl-3-pyridine amide, 1-methyl-4-pyridine amide, 1-ethyl-4-pyridine amide, 1-propyl-4-pyridine amide.

Other preferred nitrogen-containing compounds are where n=1, R₇ is hydrogen and R₆ is hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl.

The tertiary amines used according to the invention are:

(1) N(R₁ R₂ R₃) wherein R₁, R₂ and R₃ independently are as defined above, Preferred nitrogen-containing compounds according to this type of the invention are octyldimethyl amine, nonyldimethyl amine, decyldimethyl amine, undecyldimethyl amine, dodecyldimethyl amine, tridecyldimethyl amine, tetradecyldimethyl amine, pentadecyldimethyl amine or hexadecyldimethyl amine.

(2) A heterocylic group containing at least one nitrogen atom such as C₅ H₅ R₁₀ N wherein R₁₀ is hydrogen, lower alkyl, carboxy, esterified carboxy or carboxamide. Preferred nitrogen-containing compounds are 2-pyridine amide, 3-pyridine amide and 4-pyridine amide.

Other amines are also to be contemplated to be in the scope of the invention. These include for example diamines and polyamines such as alkyllysine, alkylarginine, alkylhistidine and guanidin or derivatives thereof.

Preferred compounds according to this embodiment of the invention are ethyllysine, propyllysine, butyllysine, ethylarginine, propylarginine, butylarginine, ethylhistidine, propylhistidine and butylhistidine.

Other nitrogen-containing compounds within the scope of the invention are amino acids such as arginine, lysine, histidine, creatinine or their derivatives and polyamino acids such as polylysine and polyornithine.

Still other nitrogen-containing compounds related to the invention are cationic polymers such as aminopolysaccharides.

When the nitrogen-containing compound is a quarternary ammonium ion an ion-pair structure can be formed between the compound and inositol phosphate. This can also be the case for other nitrogen-containing compounds when they are protonated depending on the pH.

An ion-pair structure is a non-covalent interaction, for example, between one or more quarternary ammonium ions and one or more inositol phosphates, as described in the following formula:

    [IP.sub.3 ].sup.(6-n)- [N(R.sub.1 R.sub.2 R.sub.3 R.sub.4)].sub.n.sup.n+

The expression inositol phosphate comprises different isomers of inositol for example myo-inositol, allo-inositol, cis-inositol, chiro-inositol, scyllo-inositol, muco-inositol, neo-inositol or epi-inositol. Most often the inositol isomer is myo-inositol.

The degree of phosphorylation can vary between one phosphate group/inositol moiety to six phosphate groups/inositol moiety.

Preferably inositol trisphosphate isomers are used according to the invention and most preferably D-myo-inositol-1,2,6-trisphosphate (IP₃) is used.

According to the invention the inositol phosphate is most often present in a salt form or in a form where only a few of the negative charges are protonated. The salt can contain one or more cations in different combinations. Examples of cations are sodium and potassium ions. When the ion-pair structure is formed with a nitrogen-containing compound such as a quarternary ammonium ion one or more of the protons and cations will be replaced with the quarternary ammonium ions.

The pharmaceutical composition according to the invention may be administered orally, topically, rectally or by inhalation spray in dosage forms or formulations comprising conventional, non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles.

The pharmaceutical composition for oral use can be present in different forms such as capsules, granules, tablets, troches, lozenges, aqueous suspensions, dispensible powders, emulsions, syrups or elixirs. When the composition is present in liquid form capsules are preferably utilized. At the use of granules, these preferably have a size of 0.15-2 mm. Either the granules can consist of the pharmaceutical composition per se or of the composition and suitable fillers. When the pharmaceutical composition is used in a tablet form, the tablets can have a weight of 50-1500 m, for example preferably 50-800 mg and most preferably 100-500 mg.

Formulations for oral use include tablets which contain the active ingredient in a mixture with non-toxic pharmaceutically acceptable excipients. These excipients may be, for example, inert diluents, such as calcium carbonate, sodium chloride, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, potato starch, or alginic acid; binding agents, for example, starch, gelatin or acacia; and lubricating agents, for example, magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate may be employed.

Formulations for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example, peanut oil, liquid paraffin, or olive oil.

For the rectal application of the composition of this invention, typical dosage forms include suppositories, rectal gelatin capsules (solutions and suspensions), and enemas or micro-enemas (solutions and suspension). Thus, in a typical suppository formulation, any one of the compounds of this invention is combined with any pharmaceutically acceptable suppository base such as cocoa butter, esterified fatty acids, glycerinated gelatin, and various water-soluble or dispersible bases like polyethylene glycols and polyoxyethylene sorbitan fatty acid ester. Various additives like salicylates or surfactant materials may be incorporated.

For topical use, creams, ointments, gels, solutions or the like containing the compositions are employed according to methods recognized in the art.

Naturally, therapeutic dosage ranges for the compounds of the present invention will vary with the size and needs of the patient and the particular pain or disease symptom being treated.

The administration of the pharmaceutical composition according to the invention can be in a combined dosage form or in separate dosage forms.

As mentioned above the invention also relates to the use of at least one nitrogen-containing compound for the preparation of an inositol phosphate containing medicament with improved bioavailability of inositol phosphate in mammals including man at non-parenteral administration.

The nitrogen-containing compound can be a quarternary ammonium compound, a tertiary amine, a diamine, a polyamine, an amino acid or a derivative thereof as defined above.

Preferably the inositol phosphate is inositol trisphosphate and most preferably the inositol trisphosphate is D-myo-inositol-1,2,6-triphosphate.

Another embodiment of the invention relates to pharmaceutical compositions comprising a nitrogen-containing compound and other phosphorus-containing inositol derivatives. For example different types of phosphonates of inositol encounter the need of improved bioavailability after non-parenteral administration. Still another embodiment of the invention relates to pharmaceutical compositions comprising a nitrogen-containing compound and derivatives of inositol phosphates and inositol phosphonates. The derivatives could be compounds where the phosphate or phosphonate group or groups are further esterified or compounds where the hydroxyl groups on the inositol moiety are etherified or esterfied, such as alkanoyl and carbamoyl derivatives. A further embodiment of the invention is related to compositions comprising a nitrogen-containing compound and inositol derivatized with other charged groups such as carboxyl and sulphonyl. The nitrogen-containing compounds used in these embodiments belong to the same groups as disclosed above.

The invention also relates to the improvement of the penetration of cell membranes in a wider aspect than in the above definition of bioavailability. Under certain circumstances there is a need to be able to obtain an improved ability of different isomers of inositol phosphates or derivatives thereof to cross cell membranes.

Such an example is when it is desirable to let the inositol phosphate or its derivative influence different intracellular metabolic pathways. This can be the case for example when new drugs based on inositol phosphate compounds are being developed. Another example is when the knowledge of different cellular signal systems is further explored. For example it is known that some isomeric structures of inositol phosphates exist intracellularly. In many cases it is advantageous to be able to add these substances from the extracellular space in order to clarify in more detail how they effect the behaviour of the cells. This knowledge can then be used in order to develop agonistic or antagonistic compounds effecting the cellular response.

The combination of a nitrogen-containing compound such as a quarternary ammonium ion and an inositol phosphate or its derivative will facilitate the penetration across cellular membranes.

Another area is when it is desirable to facilitate the transport of nucleoside across cellular membranes.

The combination of a nitrogen-containing compound such as a quarternary ammonium ion and a nucleoside will enhance the penetration of cellular membranes.

Furthermore the invention can be used for other pharmaceuticals which suffer from low bioavailability due to the same reasons as inositol phosphates and their derivatives. One such application is a pharmaceutical composition comprising a nitrogen-containing compound and a biophosphonate or a derivative thereof useful for the treatment of bone disorders such as osteoporosis and other conditions characterized by abnormal calcium metabolism.

The bisphosphonate or the derivative thereof could be selected from the group of hydroxy ethane bisphosphonate, amino ethane bisphosphonate, dichloromethylene bisphosphonate, methylene bisphosphonate, and preferably:

1-hydroxy-3-aminopropane-1,1-bisphosphonate

1-hydroxy-6-aminohexane-1,1-bisphosphonate

4-amino-1-hydroxybutylidene-1,1-bisphonate

N-methyl-4-amino-1-hydroxy-butylidene-1,1-bisphosphonate

3-amino-1-hydroxypropylidene-1,1-bisphosphonate

1-hydroxy ethylidene-1,1-bisphosphonate

4-(hydroxy methylene-bisphosphonate)piperidine.

Another application is a pharmaceutical composition comprising a nitrogen-containing compound and a bisphosphonate or a derivative thereof useful for the treatment of cardiovascular conditions such as increased cholesterol levels and atherosclerosis. The biophosphonate or the derivative thereof could be selected from the group of alkyl bisphosphonates, alkenyl bisphosphonates, alkynyl bisphosphonates, phenyl alkyl bisphosphonates and phenoxyalkyl bisphosphonates.

Still another application is a pharmaceutical composition comprising nitrogen-containing compound and a specific bisphosphonate useful as antimicrobial agents. The bisphosphonate in this application is selected from the group of alkyl ethenylidene bisphosphonates such as tetraisopropyl ethenylidene bisphosphonate and diethyl dibutyl ethenylidene bisphosphonate. The invention can also be used for other pharmaceuticals suffering from low bioavailability such as antiviral agents. One such application is a pharmaceutical composition comprising a nitrogen-containing compound and a charged phosphorus-containing pharmaceutical or a biologically active compound such as:

phosphonoformiate

phosphonoacetate

3-azido thymidine-5-phosphate

9-(2-phosphonyl methoxy ethyl)adenine

S-9-(3-hydroxy-2-phosphonyl methoxy propyl)-adenine/cytosine

2',3'-didehydro-2,3-dideoxy thymidine

(2R,5R)-9-(2,5-dihydro-5-phosphonomethoxy)-2-furanyl adenosine and derivative thereof. The compositions are useful for the treatment of CMV-infections. HIV-infections, herpes simplex and hepatitis B.

The invention can also be used for other pharmaceuticals and biologically active compounds with low and limited bioavailability such as phosphorylated and phosphonylated sugar residues, for example hydroxy phosphonyl glucoseamine derivatives, purine and pyrimidine nucleotides and derivatives thereof for example 2'-deoxy-5-fluorouridine 5'-phosphate and oligonucleotides and derivatives thereof. Those skilled in the art will realize that the list of compounds is not exhaustive and the invention is also applicable to other pharmaceuticals and biologically active compounds comprising a phosphate or phosphonate moiety.

The invention will be explained further in connection with the embodiment examples below, however without limiting it thereto.

Example 1 shows the manufacturing of pharmaceutical composition comprising a quarternary ammonium ion and IP₃. Example 2 and 3 illustrates the determination of the bioavailability of two different quarternary ammonium ions and IP₃ after oral administration while example 4 describes the bioavailability of a composition comprising a tertiary amine and IP₃.

EXAMPLE 1

The pentasodium salt of D-myo-inositol-1.2.6-triphosphate (IP₃), 2.0 g, was converted to the acid form by a cation exchanger in acid form. To a concentrated solution of the acid form of IP₃ was added 3.7 g of N(3-dodecanoyl oxy)propyltrimethylammonium hydroxide to form an ion-pair structure consisting of 3 moles of the quarternary ammonium ion/IP₃ -moiety.

EXAMPLE 2

The bioavailability of N(3-dodecanoyloxy)propyltrimethylammonium inositol trisphosphate (obtained according to Example 1) after oral administration was determined in an experiment with pigs. Five pigs were given an intravenous injection of the sodium salt of D-myo-inositol-1.2.6-trisphosphate (IP₃) and blood samples were collected 0.25 hr, 0.5 hr, 1 hr, 4 hrs, 6 hrs, 8 hrs and 24 hrs after the injection. The blood samples were assayed for the content of IP₃ and these measurements were used for the calculation of the reference data as 100% of the substance is introduced into the blood stream after an intravenous injection.

Another five pigs were given the N(3-dodecanoyloxy)propyltrimethyl ammonium salt of IP₃ as an intraduodenal dosing. The animals were treated with Atropin® and anaesthetized with Hypnodil®/Sedaperone® whereafter a laparotomy was carried out. Blood samples were collected at the time intervals mentioned above and the concentration of IP₃ was determined in each sample. By calculating the area under the curve (AUC) from a graph where the concentration versus time is shown and comparing the obtained value with a similar calculation from the data after intravenous injection of the substance the bioavailability for the specific formulation is obtained.

Still another five pigs were given the penta-sodium salt of IP₃ orally. Blood samples were collected at the same time intervals as above and the concentration of IP₃ was determined. Following a similar procedure the AUC was determined.

The following concentrations of IP₃ were obtained after intravenous injection of the sodium salt, after oral administration of the N(3-dodecanoyl-oxy)propyltrimethyl ammonium salt and after oral administration of the sodium salt respectively.

    ______________________________________                                                 intravenous                                                                              conc. IP.sub.3 (μM) oral                                                                    oral                                                 injection,                                                                               formulation, quarternary                                                                       formulation,                                 time (hrs)                                                                             sodium salt                                                                              ammonium salt   sodium salt                                  ______________________________________                                         0       0         0               0                                            0.25    71.0      6.3             0.2                                          0.5     47.5      9.4             0.5                                          1.0     24.9      10.8            0.5                                          2.0     9.3       7.6             0.2                                          4.0     3.2       2.2             0.1                                          6.0     1.1       1.0             0.1                                          8.0     0.4       0.8             0                                            24.0    0.2       0.1             0                                            Normalized                                                                             100       46              3                                            AUC (%)                                                                        ______________________________________                                    

The bioavailability of the oral formulation consisting of the quarternary ammonium salt of IP₃ was 46%.

EXAMPLE 3

The bioavailability of N-(hexyloxycarbonyl)methyl trimethyl ammonium inositol trisphosphate after oral administration was determined with a method similar to the description in Example 2. Five pigs were given an intravenous injection of the penta-sodium salt of IP₃ while another five animals were given a formulation consisting of the quarternary ammonium salt of IP₃ as an intraduodenal dosing . Still another group of five pigs were given the penta-sodium salt of IP₃ orally. Blood samples were collected and the concentration of IP₃ were determined.

The following concentrations of IP₃ were obtained after intravenous injection of the sodium salt after oral administration of the N-(hexyloxycarbonyl)methyltrimethyl ammonium salt and after oral administration of the sodium salt respectively.

    ______________________________________                                                           conc. IP.sub.3 (μM) oral                                                                    oral                                                 intravenous                                                                              formulation, quarternary                                                                       formulation,                                 time (hrs)                                                                             injection,                                                                               ammonium salt   sodium salt                                  ______________________________________                                         0       0         0               0                                            0.25    71.0      18.2            0.2                                          0.5     47.5      29.6            0.5                                          1.0     24.9      20.1            0.5                                          2.0     9.3       12.2            0.2                                          4.0     3.2       4.3             0.1                                          6.0     1.1       1.5             0.1                                          8.0     0.4       0.6             0                                            24.0    0.2       0.1             0                                            Normalized                                                                             100       75              3                                            AUC (%)                                                                        ______________________________________                                    

The bioavailability of the oral formulation consisting of the quarternary ammonium salt of IP₃ was 75%. Irritancy test showed no toxic effects on the intestinal barriers.

EXAMPLE 4

The bioavailability of a formulation consisting of dodecyldimethyl amine and D-myo-inositol-1.2.6-trisphosphate (IP₃) after oral administration was determined with a method similar to the description in Example 2. Five pigs were given an intravenous injection of the penta-sodium salt of IP₃ while another five animals were given a formulation consisting of dodecyldimethyl amine and IP₃ as an intraduodenal dosing. Still another group of five pigs were given the penta-sodium salt of IP₃ orally. Blood samples were collected and the concentration of IP₃ were determined.

The following concentrations of IP₃ were obtained after intravenous injection of the sodium salt, after oral administration of the formulation consisting of dodecyldimethyl amine and IP₃ and after oral administration of the sodium salt of IP₃ respectively.

    ______________________________________                                                            oral formulation,                                                                           conc. IP.sub.3 (μM)                                  intravenous                                                                              tertiary amine                                                                              oral formulation,                              time (hrs)                                                                              injection,                                                                               composition  sodium salt                                    ______________________________________                                         0        0         0            0                                              0.25     71.0      2.8          0.2                                            0.5      47.5      4.2          0.5                                            1.0      24.9      4.0          0.5                                            2.0      9.3       3.8          0.2                                            4.0      3.2       1.7          0.1                                            6.0      1.1       0.8          0.1                                            8.0      0.4       0.6          0                                              24.0     0.2       0.1          0                                              Normalized                                                                              100       23           3                                              AUC (%)                                                                        ______________________________________                                    

The bioavailability of the oral formulation consisting of the amine composition was 23%. 

I claim:
 1. An inositol phosphate containing pharmaceutical composition comprising an ion-pair structure obtained by combining an inositol phosphate with a compound of the formula ⁺ N(R₁ R₂ R₃)R₅ wherein R₁, R₂ and R₃ are independentlyi) hydrogen ii) a straight or branched alkyl with 1 to 24 carbon atoms, iii) cycloalkyl with 3 to 16 carbon atoms, iv) alkenyl, with 2 to 24 carbon atoms, v) cycloalkenyl with 5 to 16 carbon atoms, vi) aryl with 6 to 24 carbon atoms or vii) aralkyl, alkaryl, aralkenyl, alkenaryl wherein alkyl, aryl and alkenyl are as previously defined,the above groups (ii) to (vii) being unsubstituted or substituted with hydroxy, oxo, alkoxy, aryloxy, carboxy, esterified carboxy, amino, substituted amino, formyl, acyl, aryloxy or acylamine and R₅ is i) --(CH₂)_(n) OCOR₆ wherein n≧2 and wherein R₆ is(1) a straight or branched alkyl with 1 to 24 carbon atoms, (2) alkenyl with 2 to 24 carbon atoms or (3) --CH₂ CH(CH₃)OCOR₁, --CH(CH₃)CH₂ OCOR₁, --CH₂ CH(OCOR₁)CH₂ OCOR₁, --CH(CH₂ OCOR₁)₂, --CH₂ CH(OH)CH₂ OCOR₁, --CH₂ CH(CH₂ OH)OCOR₁, --CH(CH₂ OH)CH₂ OCOR₁ or --CH(CH₃)COOR₁ wherein R₁ is as defined above, ii) --(CH₂)_(n) OR₆ wherein n and R₆ are as defined above iii) --(C(R₇)₂)_(n) COOR₆ wherein n≧1 and wherein R₆ is as defined above and wherein R₇ is(1) hydrogen, or (2) methyl, ethyl, propyl, butyl or pentyl iv) --C(R₇)₂ OCOR₆ wherein R₆ and R₇ are as defined above, for improvement of the bioavailability of the inositol phosphate in a mammal at non-parenteral administration.
 2. A composition according to claim 1 wherein R₁, R₂ and/or R₃ arei) hydrogen or ii) a straight or branched alkyl selected from the group of methyl, ethyl, propyl, butyl, pentyl, hexyl and/or octyl; and wherein R₅ is --(CH₂)OCOR₆ wherein R₆ is selected from hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl and/or hexadecyl.
 3. A composition according to claim 1 wherein R₁, R₂ and/or R₃ arei) hydrogen or ii) a straight or branched alkyl selected from the group of methyl, ethyl, propyl, butyl, pentyl, hexyl, hepty and/or octyl; and wherein R₅ is --(CH₂)₂ OR₆ wherein R₆ is selected from the group of hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl and/or hexadecyl.
 4. A composition according to claim 1 wherein R₁, R₂ and/or R₃ arei) hydrogen or ii) a straight or branched alkyl selected from the group of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and/or octyl; and wherein R₅ is --C(R₇)₂ COOR₆ wherein R₆ is selected from the group of hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl and/or hexadecyl and wherein R₇ isi) hydrogen or ii) a straight or branched alkyl selected from the group of methyl, ethyl, propyl and/or butyl.
 5. A composition according to claim 1 wherein R₁, R₂ and/or R₃ arei) hydrogen or ii) a straight or branched alkyl selected from the group of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and/or octyl; and wherein R₅ is --C(R₇)₂ COOR₆ wherein R₆ is selected from the group of hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl and/or hexadecyl and wherein R₇ is i) hydrogen or ii) a straight or branched alkyl selected from the group of methyl, ethyl, propyl and/or butyl.
 6. A composition according to any one of claims 1-5, wherein the inositol phosphate is at least one specific isomer of inositoltriphosphate (IP₃).
 7. A composition according to claim 6, wherein the isomer of IP₃ is D-myo-inositol-1,2,6-triphosphate.
 8. A composition according to any one of claims 1-7 in capsule, tablet or granulated form.
 9. A composition according to any one of claims 1-7 in a combined dosage form.
 10. A method for improving bioavailability in a mammal of an inositol phosphate, comprising administering to said mammal an ion-pair structure obtained by combining an inositol phosphate with a compound of the formula ⁺ N(R₁ R₂ R₃)R₅ wherein R₁, R₂ and R₃ are independentlyi) hydrogen ii) a straight or branched alkyl with 1 to 24 carbon atoms, iii) cycloalkyl with 3 to 16 carbon atoms, iv) alkenyl, with 2 to 24 carbon atoms v) cycloalkenyl with 5 to 16 carbon atoms, vi) aryl with 6 to 24 carbon atoms or vii) aralkyl, alkaryl, aralkenyl, alkenaryl wherein alkyl, aryl and alkenyl are as previously defined,the above groups (ii) to (vii) being unsubstituted or substituted with hydroxy, oxo, alkoxy, aryloxy, carboxy, esterified carboxy, amino, substituted amino, formyl, acyl, aryloxy or acylamine and R₅ is i) --(CH₂)_(n) OCOR₆ wherein n≧2 and wherein R₆ is(1) a straight or branched alkyl with 1 to 24 carbon atoms, (2) alkenyl with 2 to 24 carbon atoms or (3) --CH₂ CH(CH₃)OCOR₁, --CH(CH₃)CH₂ OCOR₁, --CH₂ CH(OCOR₁)CH₂ OCOR₁, --CH(CH₂ OCOR₁)₂, --CH₂ CH(OH)CH₂ OCOR₁, --CH₂ CH(CH₂ OH)OCOR₁, --CH(CH₂ OH)CH₂ OCOR₁ or --CH(CH₃)COOR₁ wherein R₁ is as defined above, ii) --(CH₂)_(n) OR₆ wherein n and R₆ are as defined above, iii) --(C(R₇)₂)_(n) COOR₆ wherein n≧1 and wherein R₆ is as defined above and wherein R₇ is(1) hydrogen or (2) methyl, ethyl, propyl, butyl or pentyl or iv) --C(R₇)₂ OCOR₆ wherein R₆ and R₇ are as defined above.
 11. The method according to claim 10, wherein the inositol phosphate is an isomer of inositoltriphosphate.
 12. The method according to claim 11, wherein the isomer of inositoltriphosphate is D-myo-inositol-1,2,6-tris-phosphate.
 13. The inositol phosphate according to claim 1 wherein R₁, R₂ and R₃ are independently hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl, docosyl, cyclopropyl, cyclopentyl, cyclohexyl, vinyl , allyl, propenyl, octadienyl, octenyl, decenyl, dodecenyl, tetradecenyl, hexadecenyl, octadecenyl, octadecadienyl, nonadecenyl, octadecatrienyl, arachidonyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, cyclohexadienyl, phenyl, biphenyl, aralkyl, alkaryl, aralkenyl or alkenaryl, said R₁, R₂ and R₃ being unsubstituted or substituted with hydroxy, oxo, alkoxy, aryloxy, carboxy, esterified carboxy, amino, substituted amino, formyl, acyl, aryloxy or acylamine.
 14. The inositol phosphate according to claim 1 wherein R₆ is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl, docosyl, vinyl, allyl, propenyl, octadienyl, octenyl, decenyl, dodecenyl, tetradecenyl, hexadecenyl, octadecenyl, octadecadienyl, nonadecenyl, octadecatrienyl, arachidonyl, --CH₂ CH(CH₃)OCOR₁, --CH(CH₃)CH₂ OCOR₁, --CH₂ CH(OCOR₁)CH₂ OCOR₁, --CH(CH₂ OCOR₁)₂, --CH₂ CH(OH)CH₂ OCOR₁, --CH₂ CH(CH₂ OH)OCOR₁, --CH(CH₂ OH)CH₂ OCOR₁ or --CH(CH₃)COOR₁.
 15. The method according to claim 10 wherein R₁, R₂ and R₃ are independently hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl, docosyl, cyclopropyl, cyclopentyl, cyclohexyl, vinyl, allyl, propenyl, octadienyl, octenyl, decenyl, dodecenyl, tetradecenyl, hexadecenyl, octadecenyl, octadecadienyl, nonadecenyl, octadecatrienyl, arachidonyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, cyclohexadienyl, phenyl, biphenyl, aralkyl, alkaryl, aralkenyl or alkenaryl, said R₁, R₂ and R₃ being unsubstituted or substituted with hydroxy, oxo, alkoxy, aryloxy, carboxy, esterified carboxy amino, substituted amino, formyl, acyl, aryloxy or acylamine.
 16. The method according to claim 10 wherein R₆ is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl, docosyl, vinyl , allyl, propenyl, octadienyl, octenyl, decenyl, dodecenyl, tetradecenyl, hexadecenyl, octadecenyl, octadecadienyl, nonadecenyl, octadecatrienyl, arachidonyl, --CH₂ CH(CH₃)OCOR₁, --CH(CH₃)CH₂ OCOR₁, --CH₂ CH(OCOR₁)CH₂ OCOR₁, --CH(CH₂ OCOR₁)₂, --CH₂ CH(OH)CH₂ OCOR₁, --CH₂ CH(CH₂ OH)OCOR₁, --CH(CH₂ OH)CH₂ OCOR₁ or --CH(CH₃)COOR₁. 